Yes I’ve gone on to think that because I added the one and only and then waited 5 days for fish, the bacteria may have disappeared!I thought that the Dr Tims fishless cycle required ammonium chloride ie. instant ammonia. Something like a decaying shrimp would probably do it but flakes may take a while to decompose and start producing enough ammonia.
I wonder if your cycle was either delayed or made less effective by this.